I've but this on the list to investigate. As I recall that range does represent the weapon Andy describes but at first glance it appears it **may** be used inappropriately on later vehicles although the set up for the BMD is hardly "ideal" for anything beyond "spray and pray" but it's a huge step beyond MG's fixed in boxes mounted on the fenders of a tank and therefore I do not believe this is should be the same weapon as used on the early t-54s.
FURTHER......... OK that didn't take as along as I thought it would and I still need to dig a bit deeper but what we have is one weapon representing two weapons.. the early one mounted on boxes on the fenders of the early T-54 and a later weapon mounted in Armored Personnel Carriers from the mid 60's. The reduced range was AIMED AT simulating the early weapons performance that doesn't so much apply to the later weapon which should have a "normal" game BMG range
The early T-54 used ........." two 7.62 mm (0.3 in) SG-43 medium MGs ( post WW2 -SGM ) mounted inside fixed boxes on the fenders, fired by the driver"......... the weapons mounted in the APC's is a PK. specifically designated "PKB".
I've adjusted the OOBs that were set up to use that weapon with the reduced range and given the early T-54 it's own unique weapon
Good catch